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   Tech Tips & Specs

Table  of   Contents 


Master Lock Info - PDFs 



Add Battery
Add Propane
R&M Battery Platform
R&M Jack Back OnSide Components
R&M Propane Lock

        Add Trailer Battery    

  What You Need to Know 

 ▶︎ Wiring batteries in parallel sums amp hour capacities and electrical current limits, but  retains original 12 volt output. 
▶︎ Batteries should be identical - same voltage, capacity, age, brand. Save future grief - buy 2 new, identical, deep cycle batteries. The old one is likely half-shot anyway, and this gives a complete life expectancy reset.
▶︎ Batteries should be the same state of charge. Charge 100% before install.
▶︎ The cable between positive terminals should be same length as between negatives.

▶︎ The gauge of original cables may be big enough for two. Ask your battery vendor. Cables Too Small, BAD!  Too Big, Good! They're inexpensive, don't get cheap now!
▶︎ Use standard color coding for ALL cables - RED positive (+), BLACK negative (-).
▶︎ If connecting more than 2 batteries, check manufacturer for max number that can be paralleled.  Seldom affects just 2 batteries.

How To Do It
▶︎ Mount new battery on trailer, near as possible to old one.
▶︎ Use new RED cable to connect  positive terminals, same length as negative.
▶︎ Use new BLACK cable to connect negative terminals, same length as positive.
▶︎ Connect the original RED, positive  trailer input cable to one battery and the original BLACK, negative trailer input cable  to the other (or last) battery.
▶︎ Repeat to add more paralleled batteries.

       Add Trailer Propane   

 • What You Need to Know 


There are two types of propane tanks: permanent motorhome ASME tanks, and removable DOT tanks, & 3 sizes dominate.
▶︎ 5 gallon 20# hold 4.6 gallons, 17lbs empty, 38lbs full, 36" top-to-ground.
▶︎ 7½ gallon 30# hold 7.0 gallons, 25lbs empty, 55lbs full, 42" top-to-ground.
▶︎ 10  gallon 40# hold 9.4 gallons, 32lbs empty, 72lbs full, 45" top-to-ground.

▶︎ 5 gallon used far more than all others.

▶︎ 7½ gallon are still manageable, used on larger trailers. Usually the best choice.

▶︎ 10 gallon are too heavy & awkward to transport easily, are used commercially & on jumbo RVs, not supported by R&M.

Ways to Expand Propane Capacity
▶︎ Add 2nd 5    gal 4.6 > 9.2       +100%
▶︎ Add 2nd 7½ gal,7.0>14.0       +100%
▶︎ Sub 5 gal, add (1) 7½ 4.6>7.0+  52%

▶︎ Sub 5 gal, add (2) 7½,4.6>14 +204%

▶︎ If adding 2nd 5 gallon, consider (2) 7½.  Small $, triple capacity, still manageable. 
▶︎ Upgrading tank size can usually be done without altering mounting apparatus. except racks may need a longer all-thread rod. 
▶︎ New tank: 5 gallon apprx $60, 7½ $80.


Parts to Plumb 2 Tanks  (new or used)

▶︎ (2) 5 or 7½ gallon propane tanks.

▶︎ Double Propane Tank Rack. 

▶︎ Auto-switch Propane Regulator.

▶︎  (2) Hoses, connect Tanks to Regulator.

How to Do It

▶︎ Bolt rack to tongue (Side Arms?).
▶︎ Bolt regulator to all-thread rod on rack.
▶︎ Mount (2) 5 or 7½ gallon tanks on rack.
▶︎ Connect hoses to regulator, tanks, trailer.
▶︎ Open tank valves, install Propane Lock.

     Hot-Dip Galvanization  •

 •  What You Need to Know


▶︎ Hot Dip Galvanization is the ultimate rust prevention technology! Its durability, dependability, uniformity, and effectiveness are unrivalled by any alternative! Consider:

▶︎ When steel is immersed in +830ºF molten zinc, they blend metallurgically. An outer layer of pure zinc is added, and zinc is merged into the steel itself. The zinc is ontop AND inside the steel, and this steel /zinc alloy is denser and stronger than pure steel.

▶︎ Since every part is totally immersed, every nook and cranny is uniformly covered with zinc. Spray-on's can have thin spots, missed spots, hidden crevices and inside surfaces left bare, etc.


▶︎ Galvanization protects on 3 levels: 
1. Barrier Protection: Insulates the steel from air and moisture.
2. Cathodic Protection: The zinc acts as anode and sacrifices itself to             oxidization instead of the steel.
3. Zinc Patina: If damaged, zinc oxidation builds a protective layer that reseals itand maintains protection. And it looks good indefinitely.


▶︎ Galvanizing is impervious to scrapes, scratches or impact damage, so rust can't get a foothold, expand underneath and lift and peel, the great weakness of other methods. And no maintenance is needed.

▶︎ For long-term, continuous exposure, the recommended  temperature is between -40ºF and +392ºF.

▶︎ Galvanization endures for 35 to 50 years in the harshest, salt water environments, 75 to 100 years in typical, in-land locations!.

Prod Specs
R&M Jack Back OnTop Installed
R&M Jack Back OnSide Installed
R&M's American Flag
Cust Svc

  •  JB Overlooked Benefits 

 •    What You Need to Know 

ALL  R&M  Jack Backs:

▶︎ End struggling to hold up your half-opened tailgate with one hand while wrestling heavy objects over it with the other!

▶︎ Make the previously impossible commonplace by creating completely unhindered rear access to stow objects too large, heavy or awkward to lift over a partially-opened tailgate, like dirt bikes, large compressors, generators, storage containers, recreation or sports equipment, etc.

▶︎ Remove the jack from the front of the tongue so you have room to twist & turn large objects as you guide them into the back of your truck or SUV.

▶︎ Create a convenient free area on the tongue to temporarily hold tools, security pins, bars, etc. while hitching and unhitching.

▶︎ Open up space and create clearance to step back and forth over the tongue while hitching to make the process easier, faster and more convenient!

       Monocoque Explained   

 •  What You Need to Know 

▶︎ A construction technique that magnifies the strength of its outer surfaces by placing their compressive and tensile forces in direct opposition, so they're capable of serving as the only structural members.
▶︎ Any structure where size and weight are premium can benefit from monocoque design - used in planes and race cars for over a century.
▶︎ Light, stiff, resistant to bending, has more torsional rigidity, and distributes weight more evenly than internal frame.
▶︎ Beneficial because it is light in proportion to size and strength, and its shape can conform to the logic of the component rather than geometry of the internal frame.

  •      R&M Products        •

              Specifications        •

R&M                  Setback   Wgt

Model               Min/Max  lbs

OnSide                    Any       6

OnTop                     7-17     21

OnTop Plus             7-21     25

OnTop Maxi            7-37     47

Side-to-Side             8-14     45
Side-to-Side Maxi    8-34     62​

Bat Platform 1408   Any       11

                 Dimensions         •

R&M  Model           Dimensions

OnSide                    9.75 X 10 X 3/16

OnTop                     6.75 X  20 X 2

OnTop Plus             6.75 X  24 X 2

OnTop Maxi            7.5   X  20 X 2

Side-to-Side             9.0   X  24 X 2

STS  Maxi                9.0   X  24 X 2

Bat Platform 1408  14.0    X   8 X 3/16

R&M Logo

  •      Customer Service     •

 • What You Need to Know


▶︎ R&M  provides free technical support for model selection, installations or problems via email, text or phone.

▶︎ If you have unique requirements or a challenging tongue configuration, contact R&M .

▶︎ R&M ,s flexible, modular design allows us to create custom solutions with standard parts with standard prices. There are few trailer tongue mounting requests that ​R&M  cannot satisfy!

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